Fluid pumps, whether for liquids or gases, may be of the axial type, wherein a plurality of cylinders and pistons are aligned parallel to and disposed around a central axis. The pistons are actuated successively and with their strokes overlapping in time to provide continuous pumping of the working fluid.
One method and means of controlling piston actuation is to provide a wobble plate or swash plate which is tilted relative to the pump axis and rotates relative to the pistons. The plate engages the piston and cylinder assemblies so as to actuate each one successively as rotation takes place.
Typical adjustable wobble plate designs for axial pumps generally make use of a tilt platform with a pin-ended bearing support along the tilt axis. An external mechanism is then used to rotate the pin-ended platform. This configuration requires the tilt platform and pin-ended bearing structures to support the full pump thrust loads. Structural rigidity and dynamic performance are compromised with an accompanying increase in pump vibration, noise, and small stroke dynamic stability. An unnecessarily large pump envelope is required to accommodate this approach adding to pump cost and size while further exacerbating rigidity and noise problems.